He gasped in shock as a powerful force shoved him forwards. Whatever it was had freed the horse, for the beast suddenly lurched ahead and away from him. He was freed from the wall that had been an instrument of torture and struck out without thinking – the imperative was to get away from those scraping stones, but this put him back in the heart of the churning mass.

There were houses on either side, the water lapping against upper storey windows, white faces staring from within. The ground could not be too far beneath his feet, but there might as well be an abyss under him. Shouts and cries and moans occasionally broke through the cacophony of rushing water, but he had not seen another soul in the water with him.

Silas was flung against a solid column that knocked the remaining breath from his body. He reached out, through instinct rather than intent, wondering how long he would have to endure before he finally drowned. He realised he’d caught hold of the iron crossbar at the top of a lamp-post, just beneath the extinguished gas light chamber. Silas wrapped his body around the iron pole, shivering uncontrollably. He could make out the black silhouette of the horse’s head ahead as it continued to ride the rapids. He stared after it until it disappeared.

He thought of the little attic space, of the tin bucket catching single innocent drops of water. The same stuff that had turned fearsome. There was a grim hilarity about his previous worrying whether the bucket would fill to overflowing overnight. How he wished he was in that attic now, in the bed he had paid for, with the water spilling out of the bucket. Let it go where it wanted.

For a terrifying moment, his legs were tugged, hard, then released. He clung on. A wooden container knocked against his body, floating on the waves. The moonlight showed him that it was a crib, a child’s empty wooden crib, bucking on the tide of filth. Silas held his chin high as a wave reached up to slap his cheek. He clung more tightly to the pole, a monstrous hissing filled his ears like all the demons of hell were calling to him.

Harriet couldn’t help the scream that bubbled from her mouth and nose when her ankles were seized. The door was open and she was being pulled through it, slamming her hip on the frame. She was choking, drowning. What felt like deliberate force tumbled her over and she hit the bannister of the staircase and clung to the bottom spindle.

She was dimly aware of a wavering light above her head, a glimmer in the darkness, and she hauled herself up, spindle by spindle, her head swimming. A shove from behind propelled her forwards and pain exploded in her nose as her face was smashed into the carpet. Her lungs were bursting, her nightgown tangled around her waist.

Harriet reached up and found hands, small hands that grabbed at her fingers and hair. She was breathing air again. She lay, gasping, her head on the dry carpet of the upstairs hallway, staining it with her blood. Three pairs of feet stood close by and the youngest child, only a year older than Alice, was whimpering quietly. Harriet used her last ounce of strength to pull herself out of the water, and stand, gripping the mahogany rail with both hands.